BitMEX Volume Mapping Across All Datasets

2025-02-14

Important Note on Volume Calculation

For all BitMEX datasets, the volume field is directly mapped from BitMEX’s API. However, BitMEX’s volume represents the number of contracts traded, not the volume in the base asset.

To obtain the correct base asset volume, customers must divide volume by underlyingToPositionMultiplier, which can be retrieved from our Reference endpoint. It is important to set the includeOriginalReference=true parameter when calling the Reference endpoint to retrieve this value.

• Spot Reference Endpoint: /markets/spot/exchanges/reference
• Futures Reference Endpoint: /markets/futures/exchanges/reference

Formula to Convert Volume to Base Asset

Example Calculation

Example: Futures OHLCV Data
Suppose the response from the Amberdata Futures OHLCV API contains:

{
  "instrument": "XBTUSDT",
  "exchange": "bitmex",
  "exchangeTimestamp": "2025-01-01T00:00:00.000Z",
  "open": 50000,
  "high": 50500,
  "low": 49500,
  "close": 50200,
  "volume": 100000000
}

And the response from the Reference endpoint (/markets/futures/exchanges/reference?exchange=bitmex&includeOriginalReference=true) contains:

{
  "instrument": "XBTUSDT",
  "exchange": "bitmex",
  "originalReference": {
    "underlyingToPositionMultiplier": 100000000
  }
}

To get the true volume in the base asset, apply the formula:

Why We Are Not Changing The Underlying Data Now

Correcting this at the data level would require a breaking change. We recognize the importance of this issue and may consider a structural update in the future. In the meantime, we encourage customers to apply the conversion formula above to obtain an accurate volume representation.